Image reading device

ABSTRACT

An image reader (A) includes a conductive case ( 1 ), a substrate ( 3 ) and a plurality of light receiving elements. The image reader (A) further includes a first electrode ( 10 ) formed at the case ( 1 ) and a second electrode ( 11 ) formed on the substrate ( 3 ). The case ( 1 ) is formed with an accommodation recess ( 1 g), in which a conductive contact member ( 20 ) is provided. The conductive contact member ( 20 ) is held in contact with the first electrode ( 10 ) and the second electrode ( 11 ) to electrically connect the two electrodes to each other while separating the first electrode ( 10 ) and the second electrode ( 11 ) from each other.

TECHNICAL FIELD

The present invention relates to an image reader. More particularly, theinvention relates to a device to be incorporated in a facsimile machineor a scanner as a structural part for reading an image of a document.

BACKGROUND ART

Generally, an image reader includes a case made of a synthetic resin andcertain parts mounted in the case (See JP No. 2004-193773, for example).An example of conventional image reader is shown in FIGS. 7 and 8.

Main structural parts of the conventional image reader will be describedwith reference to FIG. 7. The image reader B includes a case 101. Atransparent cover 102 and a substrate 103 in the form of an elongatedplate are mounted to an upper portion and a lower portion of the case101, respectively. A light source 104 is mounted at an end of thesubstrate 103, and a plurality of sensor IC chips 108 are mounted on thesubstrate 103 to be aligned longitudinally of the substrate 103. A lightguide 105, a reflector 106 and a lens array 107, all of which areelongate longitudinally of the case 101, are arranged in the case 101.

The operation of the image reader B will be described below. The lightemitted from the light source 104 travels through the light guide 105while being scattered little by little to the outside of the light guide105. Thereafter, the light passes through the transparent cover 102 toirradiate the document P. The light reflected at the document P passesthrough the lens array 107 and converges on a plurality of lightreceiving elements (not shown) arranged in a sensor IC chip 108. Each ofthe light receiving elements outputs an electric signal corresponding tothe amount of received light. By processing electric signals outputtedby the light receiving elements, i.e., image signals, an imagecorresponding to the document P can be obtained.

With reference to FIG. 8, the structure of the image reader B will bedescribed in more detail. The case 101 includes, at a lower portionthereof, a peripheral wall 101 a and a recess 101 b provided inward ofthe peripheral wall 101 a. The substrate 10 is fitted into the recess101 b to be mounted to the case 101. The peripheral wall 101 a alsoserves to prevent external light or a foreign matter from entering thecase 101 through a gap between the case 101 and the substrate 103.

A connector 109 is provided at one of longitudinally opposite ends ofthe substrate 103. The connector 109 is used for connecting thesubstrate 103 to an external device. The connector 109 partiallyprojects out from a longitudinal edge of the substrate 103. Theperipheral wall 101 a of the case 101 includes a cutout 101 d. Thecutout 101 d is provided for preventing the outwardly-projectingconnector 109 from coming into contact with the peripheral wall 101 a inmounting the substrate 103 to the case 101.

Generally, the dimension of the cutout 101 d is set larger than theminimum dimension required for preventing the connector 109 from cominginto contact with the peripheral wall 101 a. One of the purposes of thisis to reliably prevent the contact between the connector 109 and theperipheral wall 101 a, and the other purpose is to make it possible touse various kinds of connectors and make the structural parts of theimage reader B be widely usable. Due to this structure, when thesubstrate 103 is mounted to the case 101, a relatively large gap c1 isdefined between the cutout 101 d and the connector 109. This gap c1allows light and foreign matters from outside to enter the case 101. Toprevent this, the case 101 further includes a partition wall 101 eintegrally formed on the case 101, as shown in FIG. 8. The partitionwall 101 e separates the light receiving elements from the cutout 101 dso that light and foreign matters are prevented from coming close to thelight receiving elements in the case 101.

Described above is the structure of a conventional image reader. To bedescribed below are problems which occur in actually using an imagereader.

Image signals are liable to be influenced by electric noise. Theinclusion of noise in image signals deteriorates the image quality.Therefore, in the actual use of the device, it is necessary to takemeasures to reduce the influence of electric noise.

As one of typical countermeasures against noise, a conductive housingcan be employed as a housing for surrounding the electric circuit andthe system, and the housing is connected to the ground wiring. With thismethod, the housing is prevented from being charged, which may lead tothe enhancement of resistance to noise.

FIG. 9 shows the image reader B to which the above-describedcountermeasure against noise is applied. The case 101 is conductive andmade of polycarbonate containing carbon fiber, for example. Electrodes110A and 110B are provided on an upper surface of the substrate 103 anda lower end surface of the partition wall 101 e of the case 101,respectively. For instance, these electrodes are formed by applyingsilver paste having excellent conductivity to predetermined portions.The electrode 110A is connected to a ground wiring (not shown) providedon the substrate 103. A solder bump 111 is provided on the electrode110A. When the substrate 103 is mounted to the case 101, the solder bump111 comes into contact with the electrode 110B.

Generally, much resin components are deposited on a surface of the case101. Even when such a surface of the case is brought into contact with asolder bump, it is difficult to obtain sufficient conduction. Unlikethis, in the example shown in FIG. 9, the highly conductive electrode110B is provided on a case surface, and the size of the electrode 110Bis considerably larger than that necessary for coming into contact withthe solder bump 111. With this structure, the case 101 is electricallyconnected to the substrate 103 via the electrode 110B, the solder bump111 and the electrode 110A and hence connected to ground. Therefore, thecase 101 is not charged excessively, so that inclusion of noise in theimage signals can be prevented.

However, the above-described countermeasure against noise causes anotherproblem, i.e., causes silver particles to appear as dust. Specifically,for example, the silver particles contained in the electrode 110B mayappear as dust due to the rubbing between the solder bump 111 and theelectrode 110B. Further, the electrodes 110A and 110B may loose adhesiondue to the volatilization of a solvent, whereby silver particlesnaturally appear from the surfaces of the electrode 110A and 110B asdust. When the dust appeared in this way scatters and adheres to thelight receiving elements, the light receiving elements cannot properlydetect light, which leads to the degradation of the image readingquality.

DISCLOSURE OF THE INVENTION

An object of the present invention, which is conceived under theabove-described circumstances, is to provide an image reader whichincludes a conductive case and an electrode formed at the case and whichis capable of obtaining a proper read image by properly preventing thecharging of the case and the adhesion of conductive particles to thelight receiving elements.

To solve the above-described problems, the present invention takes thefollowing technical measures.

According to a first aspect of the present invention, there is providedan image reader comprising a conductive case, a substrate mounted to thebottom of the case, a plurality of light receiving elements for imagereading accommodated in the case and provided on the substrate, a firstelectrode formed at the case, a second electrode provided on thesubstrate, and a conductive contact member. The conductive contactmember is held in contact with the first electrode so as to cover asurface of the first electrode and also in contact with the secondelectrode. The conductive contact member electrically connects the firstand the second electrodes to each other while causing the first and thesecond electrodes to be spacially separate from each other.

With this structure, it is possible to prevent conductive particles fromappearing as dust from the first electrode, because the conductivecontact member is held in contact with the first electrode so as tocover the first electrode. Further, with this structure, even whenconductive particles of the first electrode appear as dust due to anyreason, the conductive particles do not scatter, because the surface ofthe first electrode is covered by the conductive contact member.Therefore, according to the present invention, conductive particles ofthe first electrode are prevented from adhering to the light receivingelements provided on the substrate, so that a proper read image can beobtained.

Further, with the above-described structure, excessive charging of thecase and inclusion of noise in the image signals can be avoided. This isbecause the first electrode formed at the case surface and the secondelectrode provided on the substrate are electrically connected to eachother via the conductive contact member so that the case is connected toground.

Preferably, the case is formed with an accommodation recess foraccommodating the conductive contact member. More preferably, theaccommodation recess has a size which makes it possible to automaticallyposition the conductive contact member relative to the case. With thisstructure, the conductive contact member can be easily mounted to thecase.

Preferably, the first electrode is formed on a bottom surface of theaccommodation recess.

With this structure, conduction can be reliably provided between thefirst electrode and the second electrode. This is because, when thesubstrate is mounted to the case, the conductive contact member iscompressed while being sandwiched from above and below between the firstelectrode (provided at the bottom surface of the accommodation recess)and the second electrode (provided on the substrate).

Preferably, the conductive contact member is made of conductive rubber.

With this structure, conduction can be reliably provided between thefirst electrode and the second electrode, because a relatively largecontact area can be provided between the conductive contact member andthe first electrode, and the conductive contact member and the secondelectrode. Since the conductive contact member is elastic, theconductive contact member can come into surface contact with the firstand the second electrodes.

Preferably, the conductive contact member includes an upper surface anda lower surface, and at least one of the two surfaces is irregular.

With this structure, even when the thickness of the first electrode orthe second electrode is non-uniform, the conductive contact member canabsorb the nonuniformity. Specifically, projections which form theirregularities of the surface of the conductive contact member inclinecorrespondingly to the non-uniform thickness of the electrode. As aresult, such a state in which the substrate is mounted to the case whilebeing spaced from the case can be avoided.

Preferably, a projection is formed at the bottom surface of theaccommodation recess.

This structure is advantageous for providing conduction between the caseand the electrode, because the conductive material contained in the casesuch as carbon fiber is liable to be exposed at a surface of theprojection.

Preferably, the accommodation recess is separated, by a partition wall,from an inner region of the case in which the light receiving elementsare accommodated.

With this structure, a proper read image can be obtained, becauseconductive particles of the first electrode are reliably prevented fromadhering to the light receiving elements. The first electrode formed onthe bottom surface of the accommodation recess is separated from theinner region of the case in which light receiving elements areaccommodated.

Preferably, the conductive contact member is elastically deformable.

Other features and advantages of the present invention will becomeclearer from the description of the embodiments of the present inventiongiven below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view showing an example of imagereader according to the present invention.

FIG. 2 is a sectional view taken along lines II-II in FIG. 1.

FIG. 3 is a sectional view taken along lines III-III in FIG. 1.

FIG. 4 is a sectional view taken along lines IV-IV in FIG. 1.

FIG. 5 is a sectional view (showing a principal portion) taken alonglines V-V in FIG. 3.

FIG. 6 is a perspective view showing an example of conductive contactmember.

FIG. 7 is an exploded perspective view showing an example ofconventional image reader.

FIG. 8 is a sectional view taken along lines VIII-VIII in FIG. 7.

FIG. 9 is a sectional view showing another example of conventional imagereader.

BEST MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of the present invention will be described belowwith reference to the accompanying drawings.

FIGS. 1-5 show an example of image reader according to the presentinvention. The image reader A of this embodiment can be used as astructural part of a scanner in which a document is transferred by e.g.a platen roller R (See FIG. 2). As shown in FIG. 1, the imager reader Aincludes a case 1, a transparent cover 2, a substrate 3, a light source4, a light guide 5, a reflector 6, a lens array 7, a plurality of sensorIC chips 8 and a connector 9. As shown in FIG. 3, the image reader Afurther includes an electrode 10 as a first electrode, a solder bump 11as a second electrode, and a conductive contact member 20.

The case 1 is elongate in the primary scanning direction. For instance,the case maybe made of a synthetic resin material obtained by addingabout 7 to 10% by weight of carbon fiber to polycarbonate. Because ofthe use of such a material, the case 1 is conductive.

The transparent cover 2 comprises a glass plate or a synthetic resinplate which is in the form of an elongated rectangle in plan view. Thecover 2 is mounted to an upper surface of the case 1 to close the upperopening of the case 1.

The lens array 7 includes a holder 71 made of synthetic resin andelongated in the primary scanning direction, and a plurality of lenses72 arranged in a row in the holder. For instance, each of the lenses 72may comprise a rod lens. The lens array 7 is so mounted to the case 1 asto face the lower surface of the transparent cover 2.

The light source 4 includes e.g. three kinds of LED chips for emittingred light, green light and blue light, respectively, which arecollectively resin-packaged. The light source 4 is mounted on thesubstrate 3 at one of longitudinally opposite ends of the substrate.

The light guide 5 is elongate in the longitudinal direction of the case1 and efficiently guides the light emitted from the light source 4 tothe entire area of a document read region S of the transparent cover 2.The light guide 5 may be made of a transparent acrylic resin such asPMMA or other materials having excellent light transmittance. All thesurfaces of the light guide 5 are made as a mirror surface. The lowersurface of the light guide 5 is formed with a plurality of recesses (notshown) spaced from each other by a predetermined distance in thelongitudinal direction. When the light traveling through the liquidguide 5 impinges on the recesses, the light is scattered in variousdirections. As a result, the light is emitted from a light emittingsurface 5 a toward the image read region S.

The reflector 6 comprises a first member 61 and a second member 62, bothof which have an overall length generally corresponding to the overalllength of the light guide 5. The first member 61 and the second member62 of the reflector hold the light guide 5 therebetween. The reflector 6is mounted to the case 1 while integrally holding the light guide 5. Thefirst and the second members 61 and 62 may be made of white resin, forexample, and have a high reflectivity. Therefore, the light emitted fromthe light source 4 is prevented from leaking to the outside of the lightguide 5. The first and the second members 61 and 62 have reflectivesurfaces 61 a and 62 a, respectively. The reflective surfaces aredesigned to fit to the light guide 5. The light emitted from the lightsource 4 travels while repeating total reflection at the mirror surfacesof the light guide 5 or reflection at the reflective surfaces 61 a, 62 aand is then emitted from the light emitting surface 5 a of the lightguide 5 to irradiate the document read region S.

The plurality of sensor IC chips 8 are mounted on the substrate 3 to bealigned in the primary scanning direction (longitudinal direction of thesubstrate 3) in contact with each other. Each of the sensor IC chips 8comprises a semiconductor chip including an integrated circuit providedwith a plurality of light receiving elements 81. When the substrate 3 ismounted to the bottom of the case 1, the sensor IC chips 8 areaccommodated in an inner region 1 r of the case 1. In this state, thelight receiving elements 81 are located at positions at which the lightpassed through the lens array 7 can be received. Each of the lightreceiving elements 81 has a photoelectric conversion function. Thus,when each of the light receiving elements 81 receives light at apredetermined light receiving surface, the light receiving elementoutputs a signal of the level corresponding to the amount of receivedlight.

The substrate 3 is in the form of a strip made of ceramic material. Theconnector 9 for connecting the substrate 3 to an appropriate externaldevice is provided at one of longitudinally opposite ends of thesubstrate. On the substrate 3, a wiring (not shown) for electricallyconnecting the connector 9 to the light source 4 and the sensor IC chips8 are provided. The power supply to the light source 4 and signal inputand output with respect to the sensor IC chips 8 are performed throughthe wiring and the connector 9.

As shown in FIG. 2, the substrate 3 is so mounted to the case l as toclose the lower opening of the case 1. Specifically, a lower portion ofthe case 1 is formed with a downwardly projecting peripheral wall 1 a,and the substrate 3 is mounted to the case 1 by fitting into a recess 1b defined inside of the peripheral wall 1 a. The recess 1 b has a flatbottom surface 1 c. By holding the substrate 3 in contact with thebottom surface 1 c, external light or dust are prevented from passingbetween the case 1 and the substrate 3 to reach the inner region 1 r ofthe case 1.

As shown in FIGS. 1, 4 and 5, the peripheral wall 1 a is formed with acutout 1 d. The cutout is provided at a location corresponding to theconnector 9. The provision of the cutout 1 d prevents the connector 9from coming into contact with the peripheral wall 1 a in mounting thesubstrate 3 to the case 1. The dimension of the cutout 1 d is set largerthan the minimum dimension required for preventing the connector 9 fromcoming into contact with the peripheral wall 1 a. Therefore, as shown inFIG. 4, when the substrate 3 is mounted to the case 1, a relativelylarge gap c1 is defined between the cutout 1 d and the connector 9.

As shown in FIG. 4, the case 1 further includes a partition wall 1 eintegrally formed on the case 1. The partition wall 1 e separates thelight receiving elements from the cutout 1 d. The partition wall 1 e hasa flat lower end surface 1 f which is flush with the bottom surface 1 cof the recess 1 b.

An insulating film (not shown) is formed on the obverse surface of thesubstrate 1 at portions contacting the case 1 (the portion facing thebottom surface 1 c of the recess 1 b and the portion facing the lowerend surface 1 f of the partition wall 1 e shown in FIG. 2). Theinsulating film comprises a resist film made of an epoxy resincontaining a silica-based inorganic filler in a solvent.

As shown in FIGS. 3 and 5, a rectangular accommodation recess 1 g foraccommodating the conductive contact member 20 is formed at the bottomof the case 1 at one of longitudinally opposite ends of the case 1. Theaccommodation recess 1 g is surrounded by a bottom surface 1 h and fourside surfaces 1 k, 1 m, in and 61 b and partitioned from the innerregion 1 r by the partition wall 1 e. The side surface 61 b is a surfaceof the first member 61 of the reflector 6. In this way, a side surfacesurrounding the accommodation space in this embodiment comprises asurface of a structural part other than the case 1. However, the presentinvention is not limited to such a structure. For instance, all the sidesurfaces for surrounding the accommodation space may comprise surfacesof the case 1.

As shown in FIG. 3, the bottom surface 1 h is formed with a plurality ofprojections 1 p extending longitudinally of the case 1. The electrode 10is formed on the bottom surface 1 h. The electrode 10 may be made byapplying a silver paste, for example. This silver paste may be formed bymixing silver particles with resin binder and further mixing this with aviscous medium containing an organic resin in a solvent.

The conductive contact member 20 is accommodated in the accommodationrecess 1 g of the case 1. The conductive contact member 20 may be madeof silicone rubber containing about 20 to 60 wt % of carbon fiber. Thatis, the conductive contact member 20 is made of so-called conductiverubber having conductivity. As shown in FIG. 6, the conductive contactmember 20 is in the form of a rectangular parallelepiped formed with aplurality of projections 20 a at each of an upper and a lower surfacesthereof to be symmetrical with respect to the horizontal. The thicknesst of the conductive contact member 20 is slightly larger than the depthd of the accommodation recess 1 g. The width w1 of the conductivecontact member 20 is slightly larger than the width w2 of theaccommodation recess 1 g.

As shown in FIG. 3, the solder bump 11 is formed on the substrate 3. Thesolder bump 11 is formed at a position facing the accommodation space 1g and projects upward. The solder bump 11 is connected to the wiring onthe substrate 3 and is set to the ground potential. When the substrate 3is mounted to the case 1, the conductive contact member 20 is sandwichedbetween and pressed by the bottom surface 1 h of the accommodationrecess 1 g and the obverse surface of the substrate 3 or the solder bump11. Therefore, the conductive contact member 20 is brought into surfacecontact with the electrode 10 on the bottom surface 1 h and with thesolder bump 11. As a result, the case 1 is electrically connected to thesubstrate 3 via the electrode 10, the conductive contact member 20 andthe solder bump 11 to be connected to ground.

The operation of the image reader A will be described below withreference to FIG. 1.

First, the light emitted from the light source 4 is guided into thelight guide 5 and repeats total reflection at various portions of thesurfaces of the light guide 5 or reflection at the reflective surfaces61 a and 62 a of the reflector 6. After traveling through the lightguide 5 in this way, the light passes through the light emitting surface5 a of the light guide 5 and impinges on the document read region S. Thelight reflected at the surface of the document P on the image readregion S passes through the lenses 71 of the lens array 7 and convergeson each of the light receiving elements 81 in the sensor IC chips 8. Inthis way, the image of the document P is formed on the light receivingelements 81. The image signals outputted from the light receivingelements 81 are processed, whereby the read image is obtained.

In this embodiment, unlike the conventional structure, the electrode 10provided on the case 1 does not come into contact with the solder bump11 provided on the substrate 3, and the conductive contact member 20intervenes between the electrode 10 and the solder bump 11. Therefore,the electrode 10 and the solder bump 11 do not rub against each other,so that the silver particles contained in the electrode 10 are preventedfrom appearing as dust.

Moreover, since the obverse surface of the electrode 10 (lower surfacein FIG. 3) is covered by the conductive contact member 20, it is alsopossible to prevent the scattering of silver particles from the surfaceof the electrode 10 due to the volatilization of the solvent containedin the silver paste of the electrode 10 and the deterioration ofadhesion. As a result, it is possible to properly prevent silverparticles from adhering to the light receiving elements 81 provided onthe substrate 3, so that a proper read image can be obtained.

Further, as noted above, since the case 1 is connected to ground,excessive charging of the case 1 is prevented, so that inclusion ofnoise in image signals is prevented properly.

In this embodiment, due to the provision of the accommodation recess 1 gin the case 1, the conductive contact member 20 can be properlypositioned relative to the case 1. Therefore, the mounting of theconductive contact member 20 to the case 1 is easy. Further, when thesubstrate 3 is mounted to the case 1, the conductive contact member 20is sandwiched between and pressed from above and below by the bottomsurface 1 h of the accommodation recess 1 g and the solder bump 11.Therefore, conduction is reliably established between the electrode 10on the bottom surface 1 h of the accommodation recess 1 g and the solderbump 11.

Moreover, the conductive contact member 20, which has elasticity, cancome into surface contact with the electrode 10 and the solder bump 11by being sandwiched between and pressed by the bottom surface 1 h of theaccommodation recess 1 g and the surface of the substrate 3 or thesolder bump 11. Therefore, the contact area between the conductivecontact member 20 and the electrode 10 or the solder bump 11 isincreased. This further ensures the conduction between the electrode 10and the solder bump 11 via the conductive contact member 20.

The upper and the lower surfaces of the conductive contact member 20 areirregular. Therefore, in mounting the substrate 3 to the case 1, theprojections 20 a at the upper and the lower surfaces are compressed andinclined so that the obverse surface of the substrate 3 can be broughtinto contact with the bottom surface 1 c of the case 1 and the lower endsurface 1 f of the partition wall 1. Therefore, even when the thicknessof the solder bump 11 or the electrode 10 is non-uniform, thenonuniformity can be absorbed by the inclination of the projections 20a. Therefore, such a state in which the substrate 3 is mounted to thecase 1 while being spaced from the case 1 can be prevented, so that thequality of the read image can be enhanced. As noted before, theconductive contact member 20 is symmetrical with respect to thehorizontal. Therefore, in mounting the conductive contact member 20 tothe case 1, the orientation of the upper and the lower surfaces of theconductive contact member 20 does not need to be considered, which isconvenient.

As noted before, an insulating film is formed at portions of thesubstrate 3 which are to come into contact with the case 1. Therefore,the case 1 is prevented from being unduly connected electrically to theconductive portion of the substrate 3, so that malfunction of the imagereader A is properly prevented.

In this embodiment, the partition wall 1 e separates the accommodationrecess 1 g from the inner region 1 r of the case 1 in which the lightreceiving elements 81 are accommodated. That is, the electrode 10 formedon the bottom surface 1 h of the accommodation recess 1 g is separatedby the partition wall 1 e from the inner region 1 r in which the lightreceiving elements are accommodated. Therefore, conductive particles ofthe electrode 10 are more reliably prevented from adhering to the lightreceiving elements 81, which is preferable to obtain a proper readimage.

In this embodiment, since the projections 1 p are formed at the bottomsurface 1 h of the accommodation recess 1 g, carbon fiber contained inthe case 1 is liable to be exposed at the surfaces of the projections 1b. This is advantageous for ensuring electrical conduction between thecase 1 and the electrode 10.

Although the specific embodiments of the present invention are describedabove, the present invention is not limited thereto and may be varied inmany ways without departing from the spirit of the invention.

Although the conductive contact member 20 is accommodated in theaccommodation recess 1 g in the foregoing embodiment, the presentinvention is not limited to this structure. A structure different fromthat of the foregoing embodiment may be employed as long as theconductive member comes into contact with the first electrode so as tocover the surface of the first electrode and also comes into contactwith the second electrode.

Although the accommodation recess 1 g in the foregoing embodiment isrectangular in bottom view, the configuration of the accommodationrecess is not limited to this. The accommodation recess may have aconfiguration different from that of the foregoing embodiment such as acircular shape in bottom view.

The material and configuration of the conductive contact member of thepresent invention is not limited to the foregoing embodiment and may bevaried appropriately.

Although the image reader A in the foregoing embodiment is an example tobe used as mounted in a scanner in which a document is transferred by aplaten roller, the present invention is not limited thereto. The imagereader of the present invention can be used widely for various devicesin which image reading is to be performed, such as a so-called flatbedscanner or handy scanner.

1. An image reader comprising: a conductive case; a substrate attachedto a bottom of the case; a plurality of light receiving elements forimage reading accommodated in the case and provided on the substrate; afirst electrode formed directly on the case; a second electrode providedon the substrate; and a conductive contact member; wherein theconductive contact member is held in contact with the first electrode tocover a surface of the first electrode and also in contact with thesecond electrode to electrically connect the conductive case to thesubstrate via the first electrode, the conductive contact member and thesecond electrode connected to ground while causing the first and thesecond electrodes to be spatially separate from each other.
 2. The imagereader according to claim 1, wherein the case is formed with anaccommodation recess for accommodating the conductive contact member,the accommodation recess being separated by a partition wall from aninner region of the case that receives the plurality of light receivingelements.
 3. The image reader according to claim 2, wherein the firstelectrode is formed at a bottom surface of the accommodation recess. 4.The image reader according to claim 1, wherein the conductive contactmember is made of conductive rubber.
 5. The image reader according toclaim 1, wherein the conductive contact member includes an upper surfaceand a lower surface, and at least one of the two surfaces is irregular.6. The image reader according to claim 2, wherein a projection is formedat a bottom surface of the accommodation recess.
 7. The image readeraccording to claim 2, wherein the accommodation recess is separated, bya partition wall, from an inner region of the case in which the lightreceiving elements are accommodated.
 8. The image reader according toclaim 1, wherein the conductive contact member is elasticallydeformable.
 9. The image reader according to claim 1, further comprisinga light source mounted on the substrate, a light guide for directinglight from the light source toward an image reading region, and areflector housing the light guide, wherein the conductive contact memberis also held in direct contact with the reflector.